Project description:Viruses represent major disease transmitting agents carried by human excreta and animal manure. Understanding virus inactivation is therefore essential in preventing microbial spread due to inadequate treatment of these materials. Here, we investigated the inactivation kinetics of the single-stranded (ss) RNA phage MS2, DNA phages T4 and ?X174, andthe double-stranded DNA human adenovirus in stored human urine, sludge, and animal manure, at temperatures and pH valuestypical of storage under naturally occurring conditions or mesophilic anaerobic digestion (<40 °C). The ssRNA phage MS2 was most readily inactivated in all samples compared to the other viruses tested. This is consistent with previous findings in wellcontrolled buffer solutions of similar composition, where inactivation was found to be governedby bases (NH3, carbonate, hydroxide) that catalyze the transesterification and cleavage of the ssRNA. Correspondingly, MS2 inactivation kinetics in real matrices could be adequately modelled by only taking into account the effects of temperature, pH, carbonate and ammonia on the integrity of ssRNA. DNA viruses were more persistent compared to MS2;however, inactivation in selected sludge and manure samples proceeded at faster rates compared to well-controlled buffersolutions of similar composition. This indicates a contribution of microbial or enzymatic activity to inactivation of DNA viruses. Overall, this study identifies the most important factors contributing to inactivation of viruses in human excreta and manure, and highlights the differences in inactivation kinetics and mechanisms between ssRNA and DNA viruses.
Project description:Animal models are important tools in scientific research, whereas the animals used are usually single-sex instead of mixed-sex in the experimental design. To better understand the effect of sex difference, we compared several phenotypes between male and female C57BL/6 mice, including behavioral tests, plasma corticosterone levels, adult neurogenesis, and RNA-seq. The experiments were performed under non-stressed and chronic-stressed conditions, respectively. Overall, our results showed several differences between male and female mice in sensorimotor performance while little difference was found in anxiety, depression, learning, and memory. We did not observe a significant difference in adult neurogenesis. There was a sex difference in plasma corticosterone levels under chronic stress conditions, either in 30 min after the restraint stress or after 60min of the recovery. Yet, the corticosterone levels were equivalent between the sexes under non-stressed conditions at any time point. Furthermore, the results of RNA-seq identified the differential expression genes between male and female mice under non-stressed or chronic-stressed conditions.